2012 saw the culmination of "Phase One" in Marvel Studios' plan for universal domination, with the release of The Avengers. It's pretty amazing to look back at 2008 and see how Iron Man and The Incredible Hulk created an unstoppable juggernaut. And along the way, the Marvel crew has created huge amounts of breathtaking concept art.

Here are some pieces of concept art that sum up the whole history of the Marvel movie universe.

Iron Man (2008)

Including early designs for the Iron Monger armor, back when it was still referred to as the Crimson Dynamo armor. Plus early War Machine designs. And a really good look at how Ryan Meinerding created a Mark I armor that looked as though it could have been scavenged from other Stark Industries weapons.

Incredible Hulk (2008)

Aaron Sims reinvented the Hulk and the Abomination. For the Hulk, says Sims, "I started with a more basic human look but still keeping with the iconic Hulk and it grew from there. After that, I went really over the top to see how far we could push it, and then pulled it back to what you see in the movie." He adds, "The Abomination went many different directions. Some at the beginning were closer to the comic, but everyone felt it didn't make sense to what happening in the movie. They wanting it to look like it was growing from within and the bones and muscle would break through the skin."

The Mark VI design is meant to be a bit sleeker than the Mark III. What Adi Granov and Phil Saunders did with the Mark III is so successful and was received so well, though, it became a struggle with how far to deviate from it. It was decided early on that we wouldn't change the helmet and just try and find a way to make the rest of the suit feel a little bit more advanced. There was talk changing the RT to a triangle shape for the final suit design, and so I was trying to come up with a design that could work with both a triangle and a circle.

The whole point of Whiplash in the movie was to prove that someone out there could develop the power source which only Tony thinks he owns. The RT tech is discovered by Whiplash - that's the important part - not the suit as in the comics. The potential for any armor or any weapon is suddenly out of control and in the hands of Whiplash - an allegorical reference to the present-day proliferation of nuclear weapons. The idea of whips is obvious, and early on Jon Favreau referred all of us to a few guys on the internet who were great with whips.

Thor (2011)

Says Visual Development Supervisor Charlie Wen: In the beginning of it, because we were still trying to find it, I think I was more interested in trying to maintain the Norse side of things as much as I could, as much as I thought I could get away with, and it was trying to get that balance of how much do you really need to keep of the comic book design and not lose [it]. Because you're trying to reestablish an icon, just in a different medium, you know? And so it was kind of important to make sure we didn't go too far Norse. [We looked at what] were all the recognizable things about Thor. His discs, obviously. Do you keep the helmet or not? Even [the] cape, that was also an issue. How much of it can you get away with trying to change while trying to recreate him to both the Norse side of things of things and the [comics'] world.

On a very simple design basis, most of our "Iron Man" stuff is dependent on function, and "Thor's" stuff is supposed to be function we don't necessarily understand. Function doesn't necessarily come into it; it's more of a unifying aesthetic than anything, a fantastical concept of what these gods would wear out to battle and around the house.

When I was first approached by Marvel about the project, the first challenge that jumped out at me was how to make all of these characters from so many disparate worlds and visual vocabularies coexist in our world of today. With the Iron Man films, Marvel had been so successful creating a seamless reality where the world felt plausible and even though IM's tech was other worldly, it still felt grounded. You could tell how much care had been taken to maintain a truth in the visuals.

I felt a tremendous sense of responsibility, to all of the incredibly talented artists who had worked on the films before me, to deliver a world that was balanced and cohesive, and could contain all of these different visual threads. Honestly the first image in my head was the Avengers, gathered in battle, the group shot on the viaduct, and how to make that work.